Patent GB-654371-A (GB)
Title: Magnetic recording and reproducing
IPC: G11B15/44
Filed: 1947-08-08
Abstract: 654,371. Magnetic recording and reproducing apparatus. MAGNETONE, Inc. Aug. 8, 1947, No. 22028. Convention date, June 12, 1940. [Class 40 (ii)] In a magnetic record transducing apparatus, a sequence of transducing operations, such as a reproducing operation following a recording operation, is automatically effected by means of a synchronizing device which is set in motion with the initial movement of the record medium and which produces a control signal at a desired moment to initiate the next part of the sequence cycle and to stop the transducing operation at the end of the transducing cycle. In one embodiment, a recording operation followed by a reproducing operation of the recording maybe obtained by a coin-operated mechanism in which the insertion of a coin of some particular value may permit a recording to be made and then reproduced one or more times, while the insertion of a coin of some higher value permits as many recordings and/or reproductions to be made in a given period of time as desired. For instance, if a coin of the lower value be inserted in the coin shoot 6-12, Fig. 1, the switch 4-10 is momentarily closed to secure operation of a relay 4-40 which is thereupon locked by its parallel contacts 4-43. At the same time, the contacts 4-41 complete a circuit from the main supply terminals + + and - - to the motor 13 whereby the magnetic medium 9 is set in motion relative to the transducer 15 and erazing head 17, while the contacts 4-42 complete the energizing circuit of a synchronizing circuit of a synchronizing motor 4-03, which drives a shaft carrying cams 4-01, 4-02. The cam 4.01 operates contacts, which are parallel to 4-41, 4-42, and are immediately closed so as to maintain the tape driving motor 13 and the synchronizing motor 4-03 after the circuit of relay 4-40 is broken. The cam 4-02 has raised portions 4-29 corresponding to the length of the record carrier or tape 9 and while the switch members operated by the portions 4-29 are held in their flexed position the relay 4-40 is held on and a circuit is maintained through a relay 20 to hold the contacts 25, 26, 27 in the reproducing position in which the transducer 15, the erazing head 17 and the microphone 22 are connected to the terminals OT, OB, IN, respectively, of the amplifier 24. At the same time a supply circuit is maintained to a " recording " indicator lamp 3-29 marked "SPEAK." When the cam 4-02 has turned through an angle corresponding to the raised portion 4-29, the switch members controlled thereby are released, so that the switch members 25, 26, 27 are released to the reproducing position in which the transducer 15 and reproducer 23 are connected to the terminals IN, OT, respectively, of the amplifier 24. At the same time the circuit of the relay 4-40 is broken and the supply circuit to the " recording " indicator lamp 3-29 is changed over to the "reproducing " indicator lamp 3-19 marked "LISTEN." In the case illustrated in Fig. 1, the peripheral length of the cam depression between the projections of cam 4-02 is twice that of the projections so that each recording is reproduced twice after completion of the recording, after which the switch contacts flexed by cam 4-01 are opened to stop the motor 13 and 4-03, whereupon all the circuits are restored to their original condition. If a coin of a higher value be inserted in the coin shoot, a selective control mechanism 5-00 is brought into operation to enable the apparatus to be used for selective recording or reproducing in accordance with the desire of the user. For this purpose a further synchronizing mechanism 3-03 is provided having a dial 3-32 and a pointer 3-31 which is set by a hand to a position according to what proportion of the total length of the tape 9 on which it is desired to record. A slipping clutch 3-72 is provided between the motor 3-07 and the pointer 3-31, one revolution of the latter corresponding to the full length of the tape 9. The inserted coin momentarily closes a switch 5-10 which operates a relay 5-40 which is locked on by its parallel switch contacts 5-43, the circuit being completed through the contacts flexed by the raised part 5-2 of the cam 5-02. The flexed contacts 5-41, 5-42 complete the energizing circuits of the tape driving motor 13 and the synchronizing motor 5-03, and the contacts 5-44 establish an energizing circuit for a relay 5-50, which closes the contacts 5-55 and completes the circuit of the motor 3-07 through the contacts 3-51 when they are closed by the setting of pointer 3-31. At the same time, the energizing circuit of relay 20 is completed by contacts 5-51 of the relay 5-50 and by contacts 3-52 closed by the setting of pointer 3-31, so that the contacts 25, 26, 27 may be set to the " recording " position. The contacts 5-54 open the control circuit of mechanism 4-00 to the indicator lamps 3-19, 3-29, while contacts 5-53 connect the "reproducing" indicator lamp 3-19 to the lower contact 3-51 which is closed and lights said lamp prior to the pointer 3-31 being set for recording. Contact 5-52 of relay 5-50 connects the " recording " indicator lamp 3-29 to one terminal of the motor 3-07, so that lamp 3-29 will be lit through contact 3-51 when the motor 3-07 is energized by the setting of pointer 3-31. The rotation of motor 5-03 causes a cam 5-01 to release a switch-rod 5-1 whereby three pairs of contacts parallel to the contacts 5-41, 5-42, 5-44 are closed, so that when the contacts closed by the cam 5-02 are opened to release the relay 5-40 the energizing circuits of motors 13, 5-03 and the relay 5-50 are maintained. The user may then during the remainder of the revolution of cam 5-01 selectively record and reproduce by the operation of mechanism 3-03. While in the position shown in Fig. 1, the apparatus will reproduce, and when it is desired to record, the pointer 3-31 is set according to the amount of the total length of the tape on which it is desired to record. Other embodiments are described with reference to Figs. 2 to 17 (not shown), in which operation of the change-over switching recording to reproducing, or from one recording to another in conjunction with display or other entertainment devices, is effected by means of a synchronizing signal produced by a depression, perforation or raised part in the tape, or by a silent passage or supersonic signal thereon. Some embodiments, Figs. 5 and 11 (not shown), utilize several endless tapes driven by separate motors, automatic switching of the motors and sound circuits being effected under the control of pre-selector switches. Fig. 9 (not shown), features an embodiment in which a single length of tape is driven backwards and forwards from one spool to another, and carries two tracks, one for use in each direction. Figs. 13, 14 and 15 (not shown) feature apparatus in which a multiplicity of such tapes are used, but in which each tape has one track only, half of the tapes carrying tracks which are reproduced in one direction of winding while the other half are being rewound, and vice versa.